It is well known that ultraviolet light in the proper dose kills most bacteria, algae, viruses, mold spores, and other microorganisms found in liquids such as water. There have been many ultraviolet water sterilization systems proposed to take advantage of this phenomenon. U.S. Pat. Nos. 4,769,131 and 4,968,437 issued to Noll et al. disclose an ultraviolet purification system in which water is pumped through tubes helically coiled around an ultraviolet lamp to provide maximum ultraviolet exposure time for a given tube length to create a relatively compact sterilization system for potable water.
This system as well as other known systems suffer from a number of drawbacks which make them less than ideal solutions to the water purification problem.
On problem common to these systems is that the liquid must be pumped under pressure past the ultraviolet lamp both before and after filtration. This requires a relatively large pump that draws a relatively great amount of power. In addition, such systems are typically designed to treat tap water, and are incapable of taking water from another source such as collecting water dripping off a condensing coil of a dehumidification or air conditioning system.